This ACTG study will evaluate the long-term safety, efficacy, and tolerance of Zidovudine to treat subjects with symptomatic HIV infections as manifested by early AIDS-related complex using the following criteria. (1) Prevention or delay of AIDS-defining opportunistic infections or malignancies. (2) Prevention or delay of advanced ARC. (3) Prolongation of survival. (4) Restoration of immune response. (5) Antiviral effect.